Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale.

The cadherin/catenin complex serves as an important structural component of adherens junctions in epithelial cells. Under certain conditions, ␤-catenin can be released from this complex and interact with transcription factors in the nucleus to stimulate the expression of genes that regulate apoptosis and cell cycle control. While studying the effects of the bacterial pathogen Chlamydia trachomatis on human cervical epithelial cells in culture, we observed that C. trachomatis caused the epithelial cells to separate from each other without detaching from their growing surface. The objective of the present study was to determine if this effect might involve the disruption of the cadherin/catenin complex. Primary cultures of human cervical epithelial cells or HeLa cells were infected with C. trachomatis serovar E. Cadherin-like immunoreactive materials and ␤-catenin were visualized by immunofluorescence. Preliminary studies showed that N-cadherin was the primary cadherin expressed in both the primary cultures and the HeLa cells. In noninfected cells, N-cadherin and ␤-catenin were colocalized at the intercellular junctional complexes. By contrast, the infected cells showed a marked loss of both N-cadherin and ␤-catenin labeling from the junctional complexes and the concomitant appearance of intense ␤-catenin labeling associated with the chlamydial inclusion. The results of Western blot analyses of extracts of C. trachomatis showed no evidence of cross-reactivity with the ␤-catenin antibody. These results indicate that C. trachomatis causes the breakdown of the N-cadherin/␤-catenin complex and that the organism can sequester ␤-catenin within the chlamydial inclusion. This could represent an important mechanism by which C. trachomatis alters epithelial cell function.Chlamydia trachomatis is an obligate intracellular bacterial pathogen that typically infects columnar epithelial cells but which may also infect a variety of other types of mammalian cells (24). The organism can exist as a metabolically dormant elementary body and an active reticulate body. The initial infection involves the attachment of the elementary body to the cell surface and the subsequent internalization of the organism. Inside the cell, the elementary body differentiates to form reticulate bodies that replicate within a vacuole, or "inclusion," in the cytoplasm. Chlamydiae depend on their host cell for nutritional support and can alter cellular function to evade various intracellular defense mechanisms, inhibit apoptosis, direct vesicular traffic, disrupt cytoskeletal arrangements, and alter host cell signaling mechanisms (for reviews, see references 24 and 25).Despite extensive research efforts, the exact mechanisms by which C. trachomatis causes derangements of host cell physiology remain poorly understood. During the course of studies to address this problem, we observed that infection of primary cultures of human cervical epithelial cells with C. trachomatis caused the cells to separate from each other without detaching from their growing surfa...

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The wildlife populations of Northern Central African Republic experienced precipitous declines during the 1970s and 1980s. While anecdotes coming out of the region indicate that the wildlife populations remain under serious threat, little is known about their status. An aerial sample count was carried out in the Northern Central African Republic at the end of the dry season in June 2005 and covered an 85,000 km2 complex landscape containing national parks, hunting reserves and community hunting areas. Results show a dramatic decline of wildlife since the previous survey in 1985. In 20 years, large mammals’ numbers decreased by 65%, probably because of poaching and diseases brought by illegal cattle transhumance. Elephant (Loxodonta africana) and Buffon kob (Kobus kob) populations showed the greatest decline (over 80% each), while buffalo (Syncerus caffer), roan antelope (Hippotragus equinus) and Giant Lord’s Derby Eland (Taurotragus derbianus) populations seem stable or increasing over these last 20 years. The analysis of the wildlife population distribution by status of the different types of protected areas (national parks, hunting areas) showed that individual encounter rates of elephant and buffalo were lower in national parks than in neighbouring hunting areas, while those for roan, giraffe (Giraffa camelopardalis) and Buffon kob were higher in the national parks.

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